Grammer2/src/gfx/bigsprite.z80

#define spritetmp 8000h
sprite_width  = spritetmp+0
sprite_x      = spritetmp+1
sprite_mask0  = spritetmp+2
sprite_mask1  = spritetmp+3
sprite_method = spritetmp+4


rshiftHA_7:
  rr h \ rra
  rr h \ rra
  rr h \ rra
  rr h \ rra
  rr h \ rra
  rr h \ rra
  rr h \ rra
  ex de,hl
  ld e,a
  ret
spritemask:
  .db $00,$80,$C0,$E0,$F0,$F8,$FC,$FE
call_ix:
  jp (ix)

sprite:
;Inputs:
;     A is the method:
;        0=Overwrite
;        1=AND
;        2=XOR
;        3=OR
;        5=Erase
;     B is the X-coordinate
;     C is the Y-Coordinate
;     DE points to the sprite
;     H is the height
;     L is the width
;     (gbuf_temp) is the buffer to which to draw

  ld (sprite_method),a
;First check if the sprite is on-screen in the horizontal direction
  ld a,c
  cp 64
  jr c,+_
  add a,h
  ret nc
  ld h,a
  push hl
  xor a
  ld h,a
  sub c
  ex de,hl
  add hl,de
  dec a
  jr nz,$-2
  ex de,hl
  pop hl
  xor a
  ld c,a
_:
;Next check h+c<=64
  ld a,64
  sub c
  cp h
  jr nc,+_
  ld h,a
_:

;Make sure the height is not now 0
  ld a,h
  or a
  ret z

;Save the width and height of the sprite
  push hl               ;height,width
  ld h,b
  ld (sprite_width),hl  ;x,width
  push de               ;sprite pointer

;Set up a pointer to the routine for shifting the  routine for shifting the sprite data
  ld ixh,rshiftHA_7>>8
  ld a,h
  cpl
  and 7
  ld l,a
  add a,a
  add a,l
  add a,rshiftHA_7&255
  ld ixl,a
#if (rshiftHA_7&255)>234
  jr nc,$+4
  inc ixh
#endif



  ld a,b
  and 7
  ld de,spritemask
  add a,e
  ld e,a
#if spritemask&255>248
  jr nc,$+3
  inc d
#endif
  ld a,(de)
  ld (sprite_mask0),a
  cpl
  ld (sprite_mask1),a
;
;
  ld a,c
  add a,a
  sbc a,a
  ld h,a
  ld a,b
  ld b,h
  ld l,c
  add hl,hl
  add hl,bc
  add hl,hl
  add hl,hl
  ld c,a
  add a,a
  sbc a,a
  ld b,a
  ld a,c
  sra c
  sra c
  sra c
  add hl,bc
  ld bc,(gbuf_temp)
  add hl,bc

  pop de
  pop bc
  ;B is height
  ;C is width
  ex de,hl

_:
  push bc   ;height,width
  push de   ;gbuf ptr
  push hl   ;sprite data pointer
  ld a,(sprite_x)
  ld c,a
  add a,8
  ld (sprite_x),a
  call spritemethod
  pop hl
  inc hl
  pop de
  inc de
  pop bc
  dec c
  jr nz,-_
  ret


spritemethod:
  ld a,(sprite_method)
  dec a
  jp z,spriteloop_AND
  dec a
  jp z,spriteloop_XOR
  dec a
  jp z,spriteloop_OR
  sub 2
  jp z,spriteloop_Erase


spriteloop_Overwrite:
  push bc
  push hl
  ld h,(hl)
  xor a
  call call_ix
  ld a,c
  cp 96
  jr nc,+_
  ld a,(sprite_mask0)
  and (hl)
  or d
  ld (hl),a
  ld a,c
_:
  inc hl
  add a,8
  cp 96
  jr nc,+_
  ld a,(sprite_mask1)
  and (hl)
  or e
  ld (hl),a
_:
  ld bc,11
  add hl,bc
  ex de,hl
  pop hl
  ld a,(sprite_width)
  ld c,a
  add hl,bc
  pop bc
  djnz spriteloop_Overwrite
  ret
spriteloop_OR:
  push bc
  push hl
  ld h,(hl)
  xor a
  call call_ix
  ld a,c
  cp 96
  jr nc,+_
  ld a,(hl)
  or d
  ld (hl),a
  ld a,c
_:
  inc hl
  add a,8
  cp 96
  jr nc,+_
  ld a,(sprite_mask1)
  ld a,(hl)
  or e
  ld (hl),a
_:
  ld bc,11
  add hl,bc
  ex de,hl
  pop hl
  ld a,(sprite_width)
  ld c,a
  add hl,bc
  pop bc
  djnz spriteloop_OR
  ret
spriteloop_XOR:
  push bc
  push hl
  ld h,(hl)
  xor a
  call call_ix
  ld a,c
  cp 96
  jr nc,+_
  ld a,(hl)
  xor d
  ld (hl),a
  ld a,c
_:
  inc hl
  add a,8
  cp 96
  jr nc,+_
  ld a,(sprite_mask1)
  ld a,(hl)
  xor e
  ld (hl),a
_:
  ld bc,11
  add hl,bc
  ex de,hl
  pop hl
  ld a,(sprite_width)
  ld c,a
  add hl,bc
  pop bc
  djnz spriteloop_XOR
  ret
spriteloop_AND:
  push bc
  push hl
  ld h,(hl)
  scf \ sbc a,a
  call call_ix
  ld a,c
  cp 96
  jr nc,+_
  ld a,(hl)
  and d
  ld (hl),a
  ld a,c
_:
  inc hl
  add a,8
  cp 96
  jr nc,+_
  ld a,(sprite_mask1)
  ld a,(hl)
  and e
  ld (hl),a
_:
  ld bc,11
  add hl,bc
  ex de,hl
  pop hl
  ld a,(sprite_width)
  ld c,a
  add hl,bc
  pop bc
  djnz spriteloop_AND
  ret
spriteloop_Erase:
  push bc
  push hl
  ld h,(hl)
  xor a
  call call_ix
  ld a,c
  cp 96
  jr nc,+_
  ld a,d
  cpl
  and (hl)
  ld (hl),a
  ld a,c
_:
  inc hl
  add a,8
  cp 96
  jr nc,+_
  ld a,e
  cpl
  and (hl)
  ld (hl),a
_:
  ld bc,11
  add hl,bc
  ex de,hl
  pop hl
  ld a,(sprite_width)
  ld c,a
  add hl,bc
  pop bc
  djnz spriteloop_Erase
  ret